402 SCIENCE PROGRESS 



of my indebtedness to the writings of Herr A. E. Tornebohm, 

 late Director of the Geological Survey of Sweden, to whose 

 work the present interpretation of the complex mountain 

 structure of the High Eells of Scandinavia is so largely due. 



Scandinavia consists geologically of a foundation of Archean 

 and pre-Cambrian rocks, which are exposed over nearly all 

 Eastern and Southern Sweden ; they also form the fringe of 

 islands along the Atlantic coast and most of the rugged southern 

 provinces of Norway between Christiania and Bergen. The 

 second important constituent is a band of schists and gneisses, 

 which forms the mountain axis of Scandinavia, parallel to the 

 Atlantic coast. It was doubtless once part of an old fold- 

 mountain chain, which has now been cut down into a dissected 

 pene-plane, wherein the existing ridges are independent of the 

 heights formed by the original folds. The schists of this region 

 are associated with thick masses of sandstone and conglomerate 

 — the sparagmites and Dala Sandstone. Some of these rocks 

 were once believed, as by Murchison, to be Old Red Sandstone; 

 but they are now generally recognised as of pre-Cambrian age, 

 and accepted as members of the Algonkian system. The schist 

 belt also includes some fossiliferous rocks ; and it has been 

 held that the schists themselves are only Palaeozoic sediments 

 that have undergone thorough alteration. They were divided 

 by Tornebohm in 1872 into two series, a lower or Seve Group, 

 and an upper or Koli Group, and both were then regarded as 

 Silurian or even post-Silurian. 1 



In addition to these rocks, which are doubtfully assigned to 

 the Palaeozoic, there are some slightly altered, sedimentary rocks, 

 many of which are fossiliferous, so that their age is known. 

 These rocks include representatives of the four oldest Palaeozoic 

 systems. Here and there from Lapland to south-western 

 Scandinavia are areas of coarse sandstones, which are regarded 

 as probably Devonian. The Lower Palaeozoic rocks include 

 members of the Silurian, Ordovician, and Cambrian ; and their 

 classification is somewhat complex, as they are developed with 

 two very different facies — the eastern and the western. 



The eastern facies includes normal sedimentary rocks, of 

 which the upper members are shown by their fossils to include 



1 A. E. Tornebohm, " En geognostisk profil ofver den skandinaviska 

 fjallryggen mellan Osterund och Levanger," Ofver K. Svens. Vet. Akad. 

 1872 ; also Sver. Geol. Unders. Ajhandl. Ser. C, No. 6. 



